Reactor

Abstract

A reactor includes: a coil; a magnetic core arranged inside of the wound portion and an outer core portion arranged outside of the wound portion; and a resin molded portion. An interval between the wound portion and the inner core portion differs in a peripheral direction of the wound portion. The reactor includes an electrically insulating material that is interposed in a location at which the interval is the narrowest, and a thick portion that is interposed in a location at which the interval is the widest and forms a portion of the inner resin portion. The proportion of the interval of the narrowest location with respect to the thermal conductivity is less than the proportion of the interval with respect to the thermal conductivity.

The invention claimed is: 
     
       1. A reactor comprising:
 a coil having a wound portion; 
 a magnetic core that includes an inner core portion arranged inside of the wound portion and an outer core portion arranged outside of the wound portion; and 
 a resin molded portion including an inner resin portion that fills at least a portion between the wound portion and the inner core portion and an outer resin portion that covers at least a portion of the outer core portion, 
 wherein an interval between the wound portion and the inner core portion differs in a peripheral direction of the wound portion, the interval including a narrowest interval and a widest interval, 
 the reactor includes an electrically insulating material that is interposed in a location at which narrowest interval t1, and the widest interval t2 to form a portion of the inner resin portion, and 
 wherein a thermal conductivity of the electrically insulating material at the narrowest interval t1 is λ1, and the proportion of the interval t1 with respect to the thermal conductivity λ1 is (interval t1/thermal conductivity λ1), and 
 wherein a thermal conductivity of the electrically insulating material at the widest interval t2 is λ2, and the proportion of the interval t2 with respect to the thermal conductivity λ2 is (interval t2/thermal conductivity λ2), wherein 
 (interval t1/thermal conductivity λ1)<(interval t2/thermal conductivity λ2) is satisfied. 
 
     
     
       2. The reactor according to  claim 1 , wherein the reactor includes a thin portion that is interposed in at least a portion of the location at which the interval between the wound portion and the inner core portion is relatively narrow, the thin portion forming another portion of the inner resin portion. 
     
     
       3. The reactor according to  claim 2 , wherein the electrically insulating material and the thin portion are included at the location at which the interval between the wound portion and the inner core portion is relatively narrow. 
     
     
       4. The reactor according to  claim 1 , wherein the interval t1 of the narrowest location is 50% or less of the interval t2 of the widest location. 
     
     
       5. The reactor according to  claim 1 , wherein the wound portion has a quadrangular tube shape and the inner core portion has a quadrangular column shape, and
 the location at which the interval between the wound portion and the inner core portion is relatively narrow includes a flat plate-shaped location that is interposed between a surface of an inner peripheral surface of the wound portion and a surface of an outer peripheral surface of the inner core portion. 
 
     
     
       6. The reactor according to  claim 1 , wherein the thermal conductivity λ1 of the electrically insulating material is higher than the thermal conductivity λ2 of the thick portion. 
     
     
       7. The reactor according to  claim 1 , wherein the electrically insulating material includes at least one of insulating paper and insulating film. 
     
     
       8. The reactor according to  claim 1 , wherein the electrically insulating material includes a molded body including a resin that is the same as a constituent resin of the inner resin portion.